1. Division of Geriatric Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
2. Department of Exercise and Health Science, Incheon National University, Incheon, South Korea
3. College of Nursing, University of Colorado Anschutz Medical Campus, Aurora, Colorado
4. Department of Physical Therapy, University of Illinois, Chicago, Illinois
5. Geriatric Research Education and Clinical Center (GRECC), Department of Veterans Affairs Eastern Colorado Health Care System, Denver, Colorado